1. Field of the Invention
The present invention relates to a portable terminal such as a portable telephone, and more particularly to portable terminal having a content reproduction function such as a television broadcast reception function.
2. Description of the Related Art
Typical portable terminals include portable telephones, PDAs (Personal Digital Assistants) and the like. Portable telephones, which are representative of portable terminals, include devices now in widespread use that are provided with various additional capabilities such as an Internet access function, mail transmission/reception function, camera function, and music reproduction function in addition to the original communication functions.
In recent years, portable telephones are coming into use that have the capability to receive television (TV) broadcasts. By using the TV reception capability, a user can easily view the news or watch TV programs that he or she watches on a weekly basis even when away from home.
In some cases depending on the environment of use, however, the user may wish to suppress the sound generated from the terminal. Various devices for presenting information to a user when the generation of sound from the terminal has been suppressed are proposed as follows:
In Japanese Patent Laid-Open Publication No. 2001-267954 (JP, P2001-267954A), a portable telephone is proposed that is provided with a sound generation prevention mode as one operation mode, and further, that, when the operation mode is in the sound generation prevention mode, prevents output of the ring tone when a connection is realized and displays on a display a telephone number or characters realized by a character information service.
In Japanese Patent Laid-Open Publication No. 2004-046664 (JP, P2004-046684A), an information processor is proposed that not only prohibits sound output by means of a speaker when a speaker is accommodated inside the device, but also realizes display in which subtitles or captions corresponding to the sound that is to be supplied as output are superposed on the displayed image on a display.
In Japanese Patent Laid-Open Publication No. H06-165073 (JP, 6-165073A), a technique in a TV set having a caption function is disclosed in which, in accordance with a mute selection operation by user, the output of sound is halted, and a subtitle or caption is displayed together with a TV picture.
In Japanese Patent Laid-Open Publication No. H07-123376 (JP, 7-123376A), a technique in a teletext-receiver is disclosed in which, in accordance with a mute selection operation by the user, sound output is halted and a subtitle or caption is displayed together with a TV picture.
In some cases, the output of sound from the speaker provided in a portable telephone is not desirable depending on the user's surrounding environment, such as during travel by means of a public transportation facility. In such cases, a portable telephone of the prior art typically, in accordance with the user's selection of what is referred to as “silent mode,” prohibits the output of the ring tone from the speaker and drives a vibrator for reporting an incoming call.
If a device is considered in which a TV reception function is provided in a portable telephone having this type of silent mode capability, it naturally follows that when the silent mode has been selected, the output of sound accompanying a TV program that is being reproduced in the device should also be halted.
However, viewing a muted TV program that is meant to be accompanied by sound interferes with the comprehension of the content, and may render the function virtually meaningless to the user. In such cases, the typical mode of use is to use earphones to listen to the sound that is to be supplied as output from a speaker. However, the series of operations from connecting an earphone to the portable telephone to fitting the earphone to the user's ear can be an inconvenience to the user. Then, once fitted, the earphone may cause the user to miss onboard announcements or may hinder the user's perception of the surrounding environment, and many users therefore dislike using earphones when traveling on public conveyances such as railways.